Less favorable conditions on sandy soils in southern Oltenia (Romania) limited number of species and varieties grown in the area. Drought and high temperatures in recent years have acted as forces dehydrated plants, disturbing their metabolism. Very high air temperature, relative humidity decreased to 25%, high surface temperature and lack of rainfall during the growing season, producing an imbalance of fluid balance in plante. Excessive foliar transpiration level can dehydrate plants, close osteoles and diminuted gas exchange in the process of photosynthesis. Irrigation plants can remove the stress factor action in the area, maintaining a positive fluid balance, that evaporated water is replaced by water traspiration administered by irrigation. On the sandy soils plant photosynthesis shows a depression at noon when the action is the maximum stress factors. Research early require selection of species with short growing season, to avoid atmospheric and soil drought in July and August. Potatoes meet these requirements, and research in the present study we aimed directing agrotechnical factors (variety, irrigation, fertilization) in order to obtain high yields and efficient, in economic terms.
